Vacuum mold for contoured ceiling tile



Dec. 22, 1970 w. H. PHILLIPS 3,549,488

VACUUM MOLD FOR CONTOURED CEILLNG TILE Filed Aug; 29, 1967 INVENTORWASHINGTON H- PHILLIPS ATTOR NEY United States Patent US. Cl. 162-387 1Claim ABSTRACT OF THE DISCLOSURE A mold for the forming of a contouredceiling tile by the vacuum molding technique. A frame is prepared havingthe desired contour and this is immersed in a tank containing a liquidpulp slurry. A vacuum is pulled on one side of a contoured screenresulting in a buildup of wet pulp fibers on the reverse side of thescreen. The pulp fibers, when dried, form a contoured ceiling tile toprovide a ceiling system with a noticeable third dimension. The screenis formed by placing a plurality of small tubes side by side. The openends of the tubes form a screen-like structure on which the wet pulpfibers can build up to form the ceiling tile. The reverse end of theopen tube structure rests on a perforated design plate which iscontoured to the desired ceiling tile design.

CROSS-REFERENCE TO RELATED APPLICATION The invention herein described isdirected to an improved mold structure for use in carrying out theprocess set forth in copending application Ser. No. 664,074, filed Aug.29, 1967.

BACKGROUND OF THE INVENTION Field of the invention The invention isdirected to a mold for vacuum forming contoured ceiling tile. Theinvention contemplates specifically the use of a readily adjusted moldcontour.

Description of the prior art The majority of ceiling systems currentlyin use are the single plane or two-dimensional ceiling system whichprovides a flat ceiling structure. Recently there has been a trendtowards the development of a ceiling system which adds a thirddimension, height, to the ceiling.

The invention herein contemplates the use of a specific die for vacuumforming of contoured ceiling tiles. Through the use of a perforateddesign plate and a plurality of side-by-side tubes resting on the designplate, a specific die structure is provided for forming the contouredtiles. The ends of the side-by-side tubes form the surface upon whichthe buildup of wet pulp fibers is secured with the vacuum formingprocess. This contour at the end of the side-by-side tubes is formed bythe particular design for the perforated design plate on which the tubesrest. By readily interchangeably substituting different designs ofperforated design plates the contour of the outer ends of theside-by-side tubes is readily changed to provide different contours forthe ceiling tiles.

SUMMARY OF THE INVENTION This invention is directed to a mold used forvacuum forming a contoured ceiling tile from a wet pulp fiber slurry.The mold with the desired contour is inserted in a slurry bath and, byutilization of a vacuum, the fibers are deposited on the surface of themold to form the contoured ceiling tile. Drying of the fiber materialresults in a rigid tile structure that will hold its contoured shape.The surface of the mold that forms the contoured ceiling tile iscomposed of a plurality of side-by-side tubes whose open ends form ascreen-like structure. The tubes rest upon a perforated design platewhich is bent to form the desired contour for the ceiling tile. Thetubes readily conform to the contour of the perforated design plateresulting in this particular contour being imparted to the open ends ofthe tubes. By changing only the perforated design plate, it is possibleto secure a wide range of interchange able designs.

BRIEF DESCRIPTION OF THE DRAWING The figure is a perspective view,partially exploded, of the vacuum mold used with the process as setforth in copending application S.N. 664,074.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferred embodiment setforth in the figure there is shown the perforated support plate 2 whichseparates the suction box 4 from the mold chamber and assembly 6. Thesuction box is connected to a filtrate drain and vacuum connection 8,and this assembly is conventional in the vacuum forming art. The supportplate 2 carries the mold assembly 6 and has a plurality of perforations10 to permit the forming of a vacuum inside the mold cavity and topermit the passage of water to the filtrate drain.

The mold assembly consists of a contoured, perforated design plate 12supporting a variable contour mat 14. The contour mat 14 is composed ofa plurality of fine tubes. The tubes are placed in an adjacentside-by-side relationship and are retained in their side-by-siderelationship by clamping channels 18.

The contour surface upon which the slurry solids collect is formed bythe open ends of the fine tubes held intimately aligned and erect by theclamping channels. The open end arrangement of the tubes form in effecta screenlike structure. The other ends of the tubes rest on theperforated design plate whose contour matches that of the desireddesign. The tubes, resting upon the perforated design plate, then assumea facsimile of the contours of the plate, and the degree of registrationdepends for the most part on the diameter chosen for the tubes.

In order to change the mold design we remove the mold chamber andassembly 6 from the suction box 4. The clamping channels 18 are releasedto remove the constraining force which holds the adjacent fine tubes inposition. The perforated design plate can be removed and a substituteplate having a different design put in position. The tubes are thenpressed into contact with the substitute plate and then are reclamped inposition by the clamping channels. The unit is then reassembled to thesuction box, and the mold is now ready to be used to form a new design.The design plate can be made of any porous material that is capable ofsupporting the tubes, yet passing water and air.

Depending upon the vacuum used, the surface of the finished ceiling tilemay become pimpled if the slurry solids are pulled partly into the boresof the individual tubes. Further, a membrane permeable to liquids can beinterposed between the solids and the end of the tubes. If a number ofthe tubes are replaced by pins or rods, the slurry solids will collectaround these projections and will form either acoustic or ventilatingholes depending on the rod length. The tube diameters may be varieddepending on the surface texture desired. Also, the tubes need not beround but could be square, hex-shaped, etc. in cross-section.

The mold is used to form the ceiling tiles in the same manner as setforth in the aforementioned copending application Ser. No. 664,074. Thegreat advantage of this particular mold design is its adaptability tovarious de- SlgIlS.

It will be obvious to those skilled in the art that various changes maybe made without departing from the spirit of the invention and,therefore, the invention is not limited to which is shown in the drawingand described in the specification, but only as indicated in theappendant claim.

What is claimed is:

1. A mold for forming pulp articles by deposition from liquid pulpslurry, said mold comprising a closed box 10 References Cited UNITEDSTATES PATENTS 1,952,168 3/1934 Hawley l62383X S. LEON BASHORE, PrimaryExaminer A. DANDREA, 1a., Assistant Examiner U.S. Cl. X.R.

rality of separate tubes in side-by-side relationship with 15 1 2 -22411; 249 113 one end resting upon the perforated design plate means,

